嗜酸乳杆菌对抗生素诱导小鼠肠道菌群失调的调整作用

发布时间：2018-06-10 18:29

本文选题：肠道微生态 + 头孢曲松　；参考：《第三军医大学》2007年硕士论文

【摘要】： 长期大量使用广谱抗生素最直接、最常见的并发症就是肠道菌群失调,并由此导致腹泻或肠道感染已是不争的事实,临床上抗生素相关性腹泻(AAD)已十分普遍。目前微生态制剂作为新型治疗手段已广泛用于因肠道菌群失调引起急慢性腹泻的治疗,其根本目的在于恢复和稳定原有的微生态平衡。而具体对因抗生素诱导的肠道菌群失调具有调整作用的微生态制剂缺乏且研究报道不一致。 “培菲康”是一种新型的微生态制剂,有双歧杆菌、嗜酸乳杆菌和粪链球菌组成。其中嗜酸乳杆菌已有研究证明其具有耐酸、耐胆盐、黏附及定植抗性等优良的生物学特性。但是,它对抗生素诱导的肠道菌群失调是否具有调节作用目前还未见报道。人和动物肠道附植着大量的微生物,形成复杂而动态平衡的微生态区系。由于传统的微生物技术只能分析可培养的微生物,在研究肠道微生物生态系统时难免存在不可逾越的缺陷和不足。所以,要准确评价益生菌制剂对肠道菌群的调节功能还需其它方法的补充。基于16S rRNA基因的变性梯度凝胶电泳(denaturing gradient gel electrophoresis,DGGE)技术具有直观、快速和高通量的优点,能有效反映复杂微生物区系全貌,适合于分析复杂的微生物菌群,而且目前已被应用于肠道微生态相关研究。本实验以自“培菲康”产品分离的嗜酸乳杆菌为目标益生菌,通过连续5天大剂量抗生素头孢曲松处理SPF级BALB/c小鼠建立肠道菌群失调动物模型,运用现代分子生物学PCR-DGGE结合传统培养法观察和分析了此目标菌株对肠道菌群失调的调整作用。结果:(一)肠道菌群失调动物模型的制备:连续5天大剂量抗生素头孢曲松使肠道细菌乳杆菌、双歧杆菌、肠杆菌及肠球菌数量均下降,且停用抗生素一周内各检测菌数量未能恢复正常,与正常对照组相比,具有极显著性差异(P0.01),模型制备成功;(二)嗜酸乳杆菌对肠道菌群失调的调节作用:在成功制备动物模型基础上,嗜酸乳杆菌治疗组乳杆菌、双歧杆菌有较明显的恢复,肠杆菌数量虽也有所恢复但增长幅度不及乳杆菌和双歧杆菌,而异常增殖的肠球菌数量有所下降;DGGE图谱分析表明,各处理组具有一定程度的相似性并聚为一族,治疗组菌群多样性指数与自然恢复组相比,具有极显著性差异;同时治疗组体重、日摄食量等表观指标也均较自然恢复组要大。实验结果证实:此分离的商品化嗜酸乳杆菌对抗生素诱导肠道菌群失调具有一定的调节作用,“培菲康”具有拓展适应症的可能性。
[Abstract]:Long-term extensive use of broad-spectrum antibiotics is the most direct, the most common complication is intestinal flora disorders, and thus lead to diarrhea or intestinal infection is an indisputable fact, clinical antibiotic associated diarrhea has been very common. At present, microecological agents have been widely used in the treatment of acute and chronic diarrhea due to intestinal microflora disorders. The basic purpose of microecological agents is to restore and stabilize the original microecological balance. However, there is a lack of microecological agents that can regulate the intestinal flora disorder induced by antibiotics and the research reports are inconsistent. Peifeikang is a new microecological preparation consisting of Bifidobacterium, Lactobacillus acidophilus and Streptococcus faecalis. Lactobacillus acidophilus has been proved to have good biological characteristics such as acid tolerance, bile salt tolerance, adhesion and colonization resistance. However, whether it can regulate antibiotic-induced intestinal flora disorders has not been reported. A large number of microbes are embedded in human and animal intestines, forming a complex and dynamic microecological flora. Because traditional microbial technology can only analyze culturable microbes, it is inevitable that there are insurmountable defects and deficiencies in the study of intestinal microbial ecosystem. Therefore, it is necessary to evaluate the regulation function of probiotics on intestinal flora accurately. Denaturing gradient gel electrophoresistics (DGGE) based on 16s rRNA gene has the advantages of visual, fast and high throughput, which can effectively reflect the complete picture of complex microflora and is suitable for analyzing complex microbial flora. And it has been applied to the study of intestinal microecology. The aim of this study was to isolate Lactobacillus acidophilus from "Peifeikang" as the target probiotics. The animal model of intestinal dysbacteriosis was established by ceftriaxone, a high-dose antibiotic for 5 days, in SPF BALB / c mice. By using modern molecular biology PCR-DGGE and traditional culture method, the effects of the target strain on intestinal flora disorder were observed and analyzed. Results: 1. Preparation of animal model of intestinal dysbacteriosis: large doses of antibiotics for 5 consecutive days Ceftriaxone makes intestinal bacteria Lactobacillus, The number of Bifidobacterium, Enterobacter and Enterococcus decreased, and the number of detected bacteria did not return to normal within one week after antibiotic withdrawal, compared with the control group. There was a significant difference (P 0.01). The model was successfully prepared. (2) the regulation effect of Lactobacillus acidophilus on intestinal flora imbalance: on the basis of successful animal model, Lactobacillus acidophilus and Bifidobacterium recovered obviously in the treatment group of Lactobacillus acidophilus. Although the number of Enterobacteria recovered, the increase was not as great as that of Lactobacillus and Bifidobacterium, while the number of abnormal proliferating Enterococcus decreased. The results of DGGE analysis showed that each treatment group had a certain degree of similarity and was clustered into one group. The microbial diversity index of the treatment group was significantly different from that of the natural recovery group, and the apparent indexes such as body weight and daily food intake in the treatment group were also larger than those in the natural recovery group. The results showed that the commercial Lactobacillus acidophilus could regulate the disturbance of intestinal flora induced by antibiotics, and Peifeikang had the possibility of expanding the indication.
【学位授予单位】：第三军医大学
【学位级别】：硕士
【学位授予年份】：2007
【分类号】：R371

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